Healthy Habits May Slow Cellular Signs of Aging

TUESDAY, July 29, 2014 (HealthDay News) -- Exercise, a healthy diet and good sleep can protect the body against the negative effects of stress and slow down the aging process at a cellular level, researchers report.

A study involving hundreds of older women found that stressful events are linked to increased shortening of telomeres, the protective caps at the ends of chromosomes that affect how quickly cells age.

"We found that over a one-year period, the more stressors a woman had, the more their telomeres were likely to shorten," said lead author Eli Puterman, assistant professor of psychiatry at the University of California, San Francisco School of Medicine.

But women who maintained active lifestyles, ate right and slept well appeared to shrug off the effects of stress, with their telomeres showing no significant additional shortening, the researchers said.

Dr. Michael Speicher, professor and chairman of the Institute of Human Genetics at the Medical University of Graz in Austria, said the study "addresses a really important biological question: why a healthy lifestyle is really helpful, especially if you are exposed to stressors."

"The hopeful message is if you engage in these healthy behaviors, you can decrease some effects that stress can have on your body," he said.

Telomeres are like the plastic tips on the ends of shoelaces that keep the laces from unraveling.

Composed of DNA and protein, they protect the ends of chromosomes and keep them from unraveling. As telomeres become shorter and their structural integrity weakens, cells age and die faster.

This sort of cellular aging has been associated with age-related illnesses such as cardiovascular disease, Alzheimer's disease and cancer. One theory holds older people are more prone to develop cancer because their shortened telomeres have made their chromosomes unstable and likely to malfunction, said Speicher, who wasn't involved in the new study.

Telomeres naturally grow shorter with age, but unhealthy behaviors such as smoking, poor diet and too little sleep can cause them to shorten sooner, Puterman said. Chronic emotional stress also has been linked to shorter telomeres.